|HOUK, ALICE - Virginia-Maryland Regional College Of Veterinary Medicine (VMRCVM)|
|VERMA, SHIV - Non ARS Employee|
|HUMPHREYS, JAN - Indiana University Of Pennsylvania|
|LINDSAY, DAVID - Virginia-Maryland Regional College Of Veterinary Medicine (VMRCVM)|
Submitted to: Veterinary Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/28/2015
Publication Date: 6/30/2015
Citation: Dubey, J.P., Houk, A., Verma, S., Humphreys, J., Lindsay, D. 2015. Experimental transmission of Cystoisospora felis- like coccidium from bobcat (Lynx rufus) to the domestic cat (Felis catus). Veterinary Parasitology. 221(2015):35-39.
Interpretive Summary: Toxoplasmosis continues to be a public health problem. Cats (domestic and wild) are the main reservoirs of Toxoplasma gondii infection because they are the only hosts that can excrete the environmentally resistant stage of the parasite, the oocyst. Cats that have once excreted oocysts in feces become immune and seldom re-excrete oocysts. Cats are also hosts to several other coccidian parasites, one of which, Cystoisospora felis, can affect the immune status of the cat. Cats that have shed toxoplasma oocysts can restart shedding Toxoplasma oocysts after infection with Cystoisospora felis infection. In the present paper, the authors studied the transmission of a C. felis-like parasite in bobcats to domestic cats via infection in mice in order to better understand the biology and interaction of these parasites in the cat. The authors found that the parasite from bobcat can be transmitted to domestic cats. These results will be of interest to biologists, parasitologists, and epidemiologists.
Technical Abstract: Cystoisospora felis is an ubiquitous coccidian of cats. The domestic cat (Felis catus) is its definitive host and several mammalian and avian species are its optional intermediate/transport hosts. Nothing is known if it is transmissible to wild felids. In the present study C. felis-like oocysts were found in two naturally infected bobcats (Lynx rufus) from Pennsylvania. To study transmission of C. felis-like parasite from bobcats to domestic cats, sporulated oocysts of C. felis-like from one bobcat were orally inoculated into interferon gamma gene knockout (KO) mice, and 56 days later tissues of KO mice were fed to two coccidian-free cats; two littermate cats were uninoculated controls. The inoculated cats and controls were euthanized five and seven days later, and their small intestines were studied histologically. One inoculated cat excreted C. felis-like oocysts seven days post inoculation (p.i.) and was immediately euthanized. Mature schizonts, mature male and female gamonts, and unsporulated oocysts were found in the lamina propria of small intestine; these stages were morphologically similar to C. felis of domestic cats. No parasites were seen in histological sections of small intestines of the remaining three cats. The experiment was terminated at seven days p.i. (minimum prepatent period for C. felis) to minimize spread of this highly infectious parasite to other cats. Although oocysts of the parasite in bobcats were morphologically similar to C. felis of domestic cats, the endogenous stages differed in their location of development. The bobcat derived parasite was located in the lamina propria of ileum whereas all endogenous stages of C. felis of domestic cats are always located in enterocytes of intestinal epithelium. Characterization of DNA isolated from C. felis–like oocysts from the donor bobcat revealed that sequences of the ITS1 region was only 87% similar to the ITS1 region of C. felis from domestic cats. These results indicate that the parasite in bobcat is likely different than C. felis of cats.